CERT Coordination Center

Field Descriptions

To make the most effective use of the information contained in the vulnerability notes database, you need to know exactly what each field means. The field description help page explains how we complete each field, its format, and other information about the field. For example, it explains how we score CVSS metrics, what we mean by "date public", and the difference between a vendor statement and an addendum.

The Vulnerability Notes Database contains two types of documents: Vulnerability Notes that describe vulnerabilities that may affect one or more vendors, and Vendor Information documents (also called vendor records), that provide vendor-specific information (e.g., solutions, workarounds, references, and status) about a vulnerability. The fields in each of these documents are described below in more detail.

Vulnerability Notes Fields

Vulnerability ID

Vulnerability ID numbers are assigned to uniquely identify a vulnerability. These IDs are four to six digits long and are frequently prefixed with "VU#" to mark them as vulnerability IDs.

Vulnerability Name

The vulnerability name or title is a short description that summarizes the nature of the problem and the affected software product. While the name may include a clause describing the impact of the vulnerability, most names are focused on the nature of the defect that caused the problem to occur.

Overview

The overview is an abstract of the vulnerability that provides a summary of the problem and its impact to the reader. The overview field was not originally in the database, so older documents may not include this information.

Description

The vulnerability description contains one or more paragraphs of text describing the vulnerability.

Impact

The impact statement describes the benefit that an attacker might gain by exploiting the vulnerability. It also frequently includes preconditions the attacker must meet to be able to exploit the vulnerability.

Solution

The solution section contains information about how to correct the vulnerability. While vendor-specific patch information is recorded in the appropriate vendor information document, the solution section provides more general workarounds or solutions like "Apply a patch," or "Disable the service."

Vendor Information

This section (previously titled "Systems Affected") includes a list of vendors who may be affected by the vulnerability. The vendor name is a link to more detailed information about the vendor (a Vendor Information record) for the vulnerability in question. Additional summary information is provided for each vendor as well, including a status field indicating whether the vendor has any products that are affected, and dates when the vendor was notified and when the vendor information was last updated. The list of vendors is sorted first by status (Affected, Not Affected, and Unknown) and then alphabetically by name.

CVSS Metrics

This section provides Common Vulnerability Scoring System (CVSS) metrics and vectors. CVSS metrics appear in vulnerability notes published after March 27, 2012. We score Temporal metrics using information available at the time the vulnerability note is first published. Temporal metric information may or may not be updated after initial publication. We score Environmental metrics with a broad scope, typically some approximation of the whole internet. To use CVSS effectively, it is important to calculate your own current and specific Temporal and Environmental metrics. For vulnerability notes that cover more than one vulnerability (e.g., multiple CVE IDs), the CVSS metrics will apply to the vulnerability with the highest CVSS base metric. More information is available in the CVSS documentation. The National Vulnerability Database (NVD) also provides CVSS metrics and calculators.

References

References are a collection of URLs at our web site and others providing additional information about the vulnerability.

Credit

We acknowledge individuals who report vulnerabilities to us. This section of the document identifies who initially discovered the vulnerability, anyone who was instrumental in the development of the vulnerability note, and the primary author of the document.

Other Information

Other information included in a vulnerability note.

CVE IDs

CVE ID is used by Common Vulnerabilities and Exposures (CVE) to uniquely identify a vulnerability. The ID is also a link to additional information on the NIST National Vulnerability Database (NVD) web site about the vulnerability. While the mapping between CVE names and vulnerability IDs are usually one-to-one, in some cases multiple vulnerabilities may map to one CVE ID, or vice versa.

US-CERT Alert

If a US-CERT Alert was published for this vulnerability, this field will contain a pointer to the alert.

CERT Advisory

If a CERT Advisory was published for this vulnerability, this field will contain a pointer to the advisory. Beginning January 28, 2004, CERT Advisories became a core component of US-CERT Alerts.

Date Public

This is the date on which the vulnerability was first known to the public, to the best of our knowledge. Usually this date is when the vulnerability note was first published, when an exploit was first discovered, when the vendor first distributed a patch publicly, or when a description of the vulnerability was posted to a public mailing list. If you're aware of a public reference to the vulnerability that appeared prior to our date, please let us know. By default, this date is set to be our vulnerability note publication date.

Date First Published

This is the date when we first published the vulnerability note. This date should be the date public or later.

Date Last Updated

This is the date the vulnerability note was last updated. Since each vulnerability note is updated as we receive new information, this date may change frequently. This date is also updated when a vendor information document changes for the vulnerability note so that you can easily locate notes with new information in the vendor statements.

Severity Metric

Note: Vulnerability Notes published after March 27, 2012 will use CVSS metrics instead.

The metric value is a number between 0 and 180 that assigns an approximate severity to the vulnerability. This number considers several factors, including:

Is information about the vulnerability widely available or known?

Is the vulnerability being exploited?

Is the Internet Infrastructure at risk because of this vulnerability?

How many systems on the Internet are at risk from this vulnerability?

What is the impact of exploiting the vulnerability?

How easy is it to exploit the vulnerability?

What are the preconditions required to exploit the vulnerability?

Because the questions are answered with approximate values that may differ significantly from one site to another, users should not rely too heavily on the metric for prioritizing vulnerabilities. However, it may be useful for separating the very serious vulnerabilities from the large number of less severe vulnerabilities described in the database. The questions are not all weighted equally, and the resulting score is not linear (a vulnerability with a metric of 40 is not twice as severe as one with a metric of 20).

Document Revision

This field contains the revision number for this document. You can use this field to determine whether the document has changed since the last time you viewed it.

Vendor Information

Date Notified

This is the date that we notified the vendor of the vulnerability. In some cases, this may be the date that the vendor first contacted us, or it may be the earliest date when the vendor is known to have been aware of the vulnerability (for example, if they published a patch or an advisory).

Statement Date

This is when the vendor provided a vendor statement.

Date Updated

This is when the vendor information was last updated. As vendors produce patches and publish advisories, vendor statement, vendor information or addendum fields may be updated, affecting this date.

Status

This field indicates in broad terms whether the vendor has any products that we considers to be vulnerable or in some way affected by the vulnerability. In many cases, the relationship between a vendor's products and a vulnerability is more complex than a simple "Vulnerable" or "Not Vulnerable" status. As of April 29, 2010, the possible values for this field have been changed to better express this complexity. The new values are "Affected," "Not Affected," or "Unknown." More detailed information is often available in the Vendor Statement and following fields. Status Summary should only be used as a broad indicator of whether any products might be vulnerable or affected.

"Unknown" may indicate that we have notified the vendor (See Date Notified) but have not received or processed a response. "Unknown" may also indicate that we have not contacted the vendor, possibly because we were unable to identify a security point of contact with reasonable effort.

Status Summary is not time-dependent, that is, status does not change once the vendor has released updated software or mitigation advice.

Vendor Statement

This is the vendor's official response to our queries about the vulnerability. With little more than typographical edits, this information is provided directly by the vendor and does not necessarily reflect our opinions. In fact, vendors are welcome to provide statements which contradict other information in the vulnerability note. We suggest that the vendors include relevant information about correcting the problem, such as pointers to software patches and security advisories. We are highly confident that information in this field comes from the vendor. Statements are usually PGP signed or otherwise authenticated.

Vendor Information

This is information we are reasonably confident is from the vendor. Typically this includes public documents (that were not sent to us by the vendor) and statements that are not strongly authenticated.

Vendor References

URL references to information from the vendor about the vulnerability. This field does not appear unless we have populated it with URL references.

Addendum

This addendum is one or more paragraphs of text from us commenting on this vulnerability. These are not statements from the vendor, and they are usually present when we disagree with the vendor's assessment of the problem, when the vendor did not provide a statement, or when we believe that we can contribute something in addition to the vendor-supplied statement.

If you have additional questions about the fields contained in our database, please let us know.